Rockman Zero(2003)

Rockman Zero

Meet a poor, cowardly reploid named Zero, who's lost his memories! With the help of Lito-chan, Zero's new friend and sidekick, Zero goes on a journey to find them and recover his past.

Of course, he needs to fight his new enemies some of the time-- but you have to get him to stop hiding behind Lito-chan first.

(Source: Rockman Tanjou)